Preheat the oven to 400 degrees F.
To prepare the pork: Place cumin seeds, red pepper flakes and peppercorns in a spice grinder and grind into a fine powder. Place in a small bowl and mix in garlic powder and salt. Rub mixture all over pork. Let sit at room temperature, 30 minutes.
Meanwhile, in a medium bowl, toss potatoes with rosemary, oil and salt. In a small saucepan, bring sugar, vinegar and orange juice to a boil. Reduce heat to a simmer and continue cooking Sweet and Sour Sauce until it reduces by half, about 10 minutes. Remove from heat, swirl in butter and keep warm before using.
In a 13-inch cast iron skillet, heat 2 tablespoons vegetable oil. When pan is smoking hot, add pork and sear on both sides. Add potatoes and place in the oven until pork is cooked through and potatoes are tender, about 40 minutes.
Serve pork chops with rosemary potatoes and drizzled with the Sweet and Sour Sauce.